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2.
Microorganisms surviving for 5300 years 总被引:2,自引:0,他引:2
Abstract Recently, the well-preserved corpse of a prehistoric man with an age of approximately 5300 years bp was discovered in the Central European Alps. Analysis of materials associated with the individual has revealed the presence of microorganisms which are believed to have survived since the time of death. So far, two fungi have been isolated and identified as species of the genera Chaetomium and Absidia , respectively. In addition, we have obtained one bacterial isolate which we have identified as a Streptomyces species. Our findings demonstrate that microorganisms can remain viable under appropriate circumstances for thousands of years. The isolates may enable us to study evolutionary trends within microorganisms. 相似文献
3.
Regulation by insulin of glucose metabolism in mammary gland of anaesthetized lactating rats. Stimulation of phosphofructokinase-1 by fructose 2,6-bisphosphate and activation of acetyl-CoA carboxylase. 总被引:2,自引:2,他引:0
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The effect of insulin on glucose metabolism in mammary gland was studied by the euglycaemic/hyperinsulinaemic-clamp technique. Measurement of metabolite concentrations and enzyme activities in the mammary gland suggests two sites of action of insulin: phosphofructokinase-1 and acetyl-coA carboxylase. The increase in phosphofructokinase-1 activity could be linked to the 2-fold increase in fructose 2,6-bisphosphate concentration, since no change in maximal activity and in sensitivity of the enzyme toward fructose 6-phosphate was detected in vitro. 相似文献
4.
Fifteen ligaments taken from individuals aged between 60 and 80 years were used for the study of the histological structure, the composition of the ground substance and the biomechanical behavior. Remnants of the original duct are recognizable in the ligament as artery of the muscular type. What had been the intima is thickened and consists mainly of cell-poor, fiber-rich connective tissue, which often shows chondrification along with calcification. The biomechanical behavior of the ligaments, evaluated with the force-length and force-relaxation test, was similar to that of peripheral arteries. 相似文献
5.
Characterization of mononuclear phagocytes in schistosomal egg granulomas of athymic mice 总被引:1,自引:0,他引:1
Macrophages from schistosomal egg granulomas of athymic mice (nu/nu GM) and their euthymic littermates (nu/+ GM) were analyzed phenotypically for the expression of antigens encoded by the I-A subregion of the major histocompatibility complex and for their ability to perform as antigen-presenting cells. Only 11 to 15% of nu/nu GM expressed I-A antigens as compared to 61.5 to 75% of nu/+ GM. Although both populations of cells appeared to be equally effective as antigen-presenting cells appropriately sensitized lymphocytes in the presence of specific antigens--soluble schistosomal egg antigen (SEA) and human gamma-globulin (HGG)--only nu/nu GM, but not nu/+ GM, were found to stimulate I-A-restricted proliferation of schistosome-sensitized T cell populations in the absence of SEA added in vitro. Furthermore, nu/nu GM but not nu/+ GM were shown to exhibit significant proliferative capacity in vitro, but this phenomenon could not account for the observed difference in SEA-independent T cell stimulation. Finally, culture supernatants from nu/nu GM displayed significant thymocyte-stimulating activity, consistent with interleukin 1, which was not observed in nu/+ GM. These findings point to significant differences between nu/nu GM and nu/+ GM, which may be part of an adaptive mechanism of granulomatous reactivity in the absence of a competent T cell system. 相似文献
6.
对我国52种微茎类吸虫的18项成虫形态学特征进行主成分分析,结果表明:卵巢位置、子宫延伸位置等7项性状对第一主成分贡献较大,提示描述器官位置的指标是重要的分类依据。52个虫种在前三个主成分上的排序图显示应将其划分成4个亚科。 相似文献
7.
本文就萤叶甲亚科中柱萤叶甲属鞘翅具黑色刻点的种类进行研究,共记述4种,我国已记录3种,其中1种为新种。 相似文献
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本文报道在湛江市附近海域海鸟体内获得的两种吸虫,经鉴定为新种,命名为巨口类茎吸虫,新种Microphalloides macrostonrs sp.nov.,珊瑚多黄吸虫,新种Multivitellus coralius sp.nov. 相似文献
10.
Selenoprotein P associates with endothelial cells in rat tissues 总被引:11,自引:0,他引:11
R. F. Burk Kristina E. Hill Martha E. Boeglin Ford F. Ebner Harold S. Chittum 《Histochemistry and cell biology》1997,108(1):11-15
Selenoprotein P is an extracellular heparin-binding protein that has been implicated in protecting the liver against oxidant
injury. Its location in liver, kidney, and brain was determined by conventional immunohistochemistry and confocal microscopy
using a polyclonal antiserum. Selenoprotein P is associated with endothelial cells in the liver and is more abundant in central
regions than in portal regions. It is also present in kidney glomeruli associated with capillary endothelial cells. Staining
of selenoprotein P in the brain is also confined to vascular endothelial cells. The heparin-binding properties of selenoprotein
P could be the basis for its binding to tissue. Its localization to the vicinity of endothelial cells is potentially relevant
to its oxidant defense function.
Accepted: 6 March 1997 相似文献